I'm definitely interested in seeing your oil sample results comparing the two "Mobils." We can talk all day about additives, 4-ball wear tests, Timken tests, drain intervals, filters, etc., but the analysis on the real-world cars is what will tell the story. I'm hoping you find good things on the new SuperSyn. I would like to be able to stick w/Mobil.
I am also very interested. I just switched from being a dedicated Penzoil dino user to Mobil1 synthetic. I also installed the Mobil1 synthetic high efficiency filter with the mobil1 syn oil. I plan to use a 7000-7500 mile (what the manual says for normal driving) interval since that's what Mobil1 guarantees. If I really can go 15,000 miles on oil changes and 30,000 on filter changes, that would be significant for me. Are you going to do oil analysis at the nest drain?
There was an in-depth article in "Automotive Engineering Magazine" within the last year explaning the problem with Toyotas. It's no real secret (for anyone except Toy Engineers)
mdecampsyou will need to wait awhile for the results of the supersyn. Probably 6 months. I will to a 3 rd one for sure on a 2002 Daewoo. That won't be ready until the end of the year.
bigorange30: I hope you are not serious about going 30K on a filter. Filters are so quick, easy and inexpensive. I left the K&N in for 6 months and 6K and that was enough for me.
I had a filter on for a year, well oil too, put 5000 miles on the car in the year and same oil and filter. As it is a vertical mount I was not concerned about the drain back valve (which for me is the main failure point on filters). Anyway, cut it open, looked fine and oil analysis was fine and in line with previous results. I do try to drive at leat 10 miles every time I start the engine which may account for being okay at one year.
So, you can go one year on a fitler, after 6 months though my experience is that the drain back valve fails but on a vertical mount who cares.
I stated that the design that Toyota incorporates is excessivily hard on any oil due to the shearing effect by the addition of gears driving the ohc's. This in my book has Never been a design flaw. It has worked prior to 97 with no problems but after the lubrication industry started to incorp the "new" oils out, that's when toyota started to incur more than frequent oil sludge issues. I honestly don't think many were determined to be anything more than ownership's abuse and improper maint until just recently since these numbers had started to increase and internet conectivity giving others the ability to ban together and be heard as one.
with his new 2400 mile oil analysis showing his 30wt oil to be 20wt in that short time supported what I had been saying about tearing most oils up by 4k miles. I have always contributed this problem due the quality of the oil with the design of this engine. This engine has been proven out as an excellent engine but as someone else said, is less forgiving about neglect of maint.
The other point I bring out is sssssoooooo many people pay 20,30 and even up to $40,000 for a vehicle and yet look for the cheapest 9.95 oil change they can get. Man that just really blows my mind on this logic. Kinda like hey doc, I know I need a blood transfusion so you got some cheap stuff?.
I guess there will always be that cheap mentality on oil changes and there will continually be sludge in engines. I just hope that what I have brought to light here was that in my investigations on the toyota v6's, they 1... have an excellent motor. 2... This motor requires a little more attention than most due to its design but has never been an issue of design flaw and that the pcv valve issue they propose was nothing more than a way to inact a little more forgiveness incase of neglect and not a fix for a supposed design flaw...3...Oil quality vs Oil change intervals are a very important factor for proper maint. 4....driving habits are also very critical in selecting drain intervals.
ADC, I too am interested in your results on the new mobil supersyn but I won't put any weight on the first 2 drains as you'll still have plenty of barrier lube residual from the prior oil and that will be supporting your first 2 oil drains. So by the 3rd oil drain with supersyn, I'd suspect you may see the difference in wear if you do drive like a lot of others and stay up with traffic from light to light If you are like Those that barely ever touch the gas when first taking off, you'll never see much wear due to this not ever breaking the oils hydrodynamic properties.
This is why so many can use one type of oil and so many different analysis will be so different. Just the same, it should prove out interesting for everyone how it will work out for you.
My personal thoughts on this is that if your wear numbers do not increase by the 3rd oil drain, You are not one that gets on it in traffic much and just take your time accellerating. But if you do stay up with others from light to light, those numbers will increase. Just my opinion and predictions.
I agree there is nothing wrong with that it has been stated that if one is using a good syntheic oil that the because of its inital clean state that the filter will not already be burden to clean as intensly, yet if one had started out with a petroleum oil which inherently is dirty now compound that with the combustion process the filter has 3x the work ahead of it to keep contaminants out
Given one is using a good synthetic thats not prone to allow for sludge that would be the only reason why the filter would plug, I don't think that one would generate that much dirt to fill a filter to capacity during everyday driving. I think that the filters limitation is not the synthetic media or construction of filter, yet it's the rubber seal that gives way and looses its holding properties as the rubber seal is constantly exposed to high heat and cold it's grip is sure to loosen additionally depending on the additives used in the oil this may have a bearing on how well that seal will hold up, if one using a synthetic that seal could easily hold up to a year
However if one is using a petrol oil the sealing property may be compromised coupled with high heat and cold to only a 6month limitation.
I think I posted this in the slippery subject forum only. For months I've thought that SuperTech WAS Quaker State. Now I've found out from a Pz/QS tech that it's a separate oil made by Pz/QS (didn't ask if it's Wolf's Head, that's still a possibility).
Anyway I've asked to have the tech sheets for all SuperTech oils dino and syn. sent to me. Will post specs when I get them. Always heard that QS was PAO and Pennzoil wasn't. Don't know if I'll be able to tell that from the spec. sheets or if it really makes any difference.
tnx for bearing with me. i think it might have been that i was using ur viewpoint to see something that u were not trying to show. once more accept my apologies.
Thanks for the information. I'm pretty much of a turtle. When I'm not a "cager" and am on my cycle, its another story. Anyway, I might be suffering at the other end of the scale. Even though I have an auto, I tend to accelerate slowly when no one is behind me and I tend to run at lower than average rpm's which is not particularly good for bearings. It will be interesting to see the results here. The GrandAm is my daughter-in-law's car. She drives pretty average.
Couldn't agree with you more on the over-infatuation (IMO) with sub $1 oil prices. I'm pretty much of a miser. But I'm not penny wise and pound foolish.
As with any store brand automotive products, I figured the oil was made by one of the major companies as well. This is why I have no problem using it with confidence. Besides, I figure using any 100% synthetic oil is better for your engine than using any conventional of synthtetic blend. BTW, what is PAO? Thanks.
My question should have directed to bottgers. He said to only change a mobil1 high efficiency oil filter every other oil change and to only do oil changes ever 15 K miles if using mobil1 synthetic oil.
BTW adc100: These oil filters are not cheap. They cost $10-12 each. We're not talking about cheapo Fram filters at $2 each.
have featured quite a lot of discussion by people much more astute than I am about whether an oil is synthetic unless it's PAO (polyalphaolefin). If you're a Mobil 1 lover you think that this is the definition and that Castrol is the antiChrist for getting their bogus definition of syn. lubricants through the court. Frankly, I've never been convinced that Castrol isn't just as good, even if their oil isn't the real thing.
As far as store brands like SuperTech, their oil filters are first rate, so I have no reason to believe their oils to be bad. Personally I use the $11.99 SuperTech special oil change demanding that the Champion Labs filter be substituted for the Fram. With the exception of never using Fram filters, I have few rules in life.
I was suprised, however, to find that SuperTech oil was a different formulation than Quaker State. I e-mailed the tech because I read in another forum that SuperTech was Pennzoil.
I remember a report several years back that some auto supply sources were relabeling junk (SA non detergent) oil and selling it as name brand stuff in small auto supply stores. At least there's no chance of that happening with Wal-Mart.
I must not have explained myself very well. What I meant was if you use a cheap 100% synthetic oil like I do, you can still go 10K miles between oil changes. If you're using top notch oil like Mobil 1, you can go 15K between changes. What some were suggesting was even if you go 10K between changes, you should still change the filter every 5K. I'm saying if you're using one of the better filters like PureOne or Mobil, there's no reason to change you're filter at 5K. Just change it when you change your oil. Even if you go 15K between changes, it's all right to use the same filter for that amount of miles. These are very good filters and are made to last this long.
I had a 2001 Lexus RX300, between new and 10K miles, I had change oil/filter 4 times (do it myself 3 times, dealer one time for free), and the last time I changed to Mobil 1 at 10K due to all this engine oil sludge worries. I agreed with Bob, when you pay near 40K for a car, you should not try to save on oil change. But the oil change price at Lexus ($66) is way too high and they are not using Mobil 1 or other synth oil, and I feel better and much cheaper do it myself. After 4000 miles, I am interested to get an oil analysis, but I checked with two auto-part stores and none has heard of that. So where do you get your motor oil analyzed?
How do you change your filter w/o changing the oil? Doesn't the oil drain out through the filter port? It seems thats what would happen if you change the filter at 5K and not change the oil until 10K. I think you must be confused.
I went with these guys due to recommendations of others. Just sent a sample in. So far everyone I talked to seemed pretty checked out. Call one of the 800#s and they will give you a regional Lab.
bigorange30: You can remove the filter without draining the oil sump as long as the engine isn't running. The oil is pumped from the sump to the filter which is higher than the sump. You will get some oil spillage though, depending on the filter arrangement.
bottgers I still think that 15K is too long to go with a high efficiency filter. I would think there will be a noticable reduction in flow. That could be more critical during very cold weather. There is probably a margin of safety but I would prefer not to test it.
and have liked it. www.blackstonelabs.com. Call them directly to have them send the bottles. They are slow if ordered through the Internet. Search in the web under "oil analysis"
I would also pay the extra to get your TBN included in the analysis.
If you don't feel comfortable going that long between filter changes, by all means change them sooner. I've been doing this for quite some time now without a problem, that's another reason I feel comfortable doing this.
There are a couple of things you can look for that would help you determine how long you can go between oil and filter changes. If you have an oil pressure gage, notice where the gage usually reads, during cold weather and warm, when you first start the car, after it's been running for a while, etc. If you do this right after a fresh oil and filter change, you'll see where the normal indications should be. As you start to get a few thousand miles on the oil and the filter, when the filter starts getting saturated, you'll notice a change in the pressure. Note the mileage, and plan to make your filter changes prior to that mileage from then on.
If you don't have a pressure gage, keep an eye on the color of the oil. Notice how the oil is almost perfectly clear right after an oil change? As you put the miles on that oil, it slowly starts to darken in color. When I change my oil at the 10K mark, whether it's in my Honda or my Intrepid, the oil is a tannish brown color, but you can still see the dipstick through the oil. I never let my oil get any darker than this. If your oil is jet black when you change it, you've gone too long. At that point, the filter is saturated and the only thing it's filtering is rocks. Note the mileage for your next oil and filter change.
These methods aren't scientific, but they've been put to the test, and the results have been favorable.
I can't argue your logic. I also go by the premise that if the oil is dark it is time to change. Very unscientific, but thats my method. Also my logic on the oil filters is that they are cheap in the grand scheme things even at $10. Also they are quick to put on. Also my Sentra engine can be susceptable to (I am told) to low flow conditions with smaller oil galleries. I'm not casting doubts on your methods though.
You're absolutely right about filters being cheap in the grand scheme of things. It would certainly be worth changing your filter more often if it would mean putting off that engine replacement, or new car purchase as long as possible.
Here's a friendly dose of attitude: I subscribe to the theory that when you say "This oil is dirtier in appearance than is acceptable to me for running in my engine.", it is totally acceptable to change it-- and the filter too. (:oÞ
There's nothing saying you can't change your oil and filter every day if you'd like. I think the point is to get the most out of both, while balancing what's best for your car's engine, and your wallet.
I also can not go by the color of oil as a guide to changing it. I've now had 2 Jeep Cherokees with the 4.0L 6 cyl engine and both turn the oil black very quickly. The first one I bought used with only about 9,000 miles on it, but I still figured it was an anomaly for that vehicle. However, I bought a new 1997 JGC with the same engine and it does the exact same thing. I change oil very frequently, especially on new vehicles - but both of these get black very quickly (within 1,000 miles or so). My 02 Explorer (4.0L 6 cyl) still looks pretty good even on the one 4,000 mile change I did. All the others have been 3,000 miles or less. Just an FYI.
I thought the folks on this board had pretty well agreed, and in my mind, established, that the color/darkness of the oil was no indicator of the need to change it. Isn't that the view held by just about everyone here?
I am in agreement with blueudevils, the color of your oil is not a good indicator of its condition - oil analysis will verify this. Of course, it never hurts to change your oil out before it really needs changing.
Your view on using oil color/darkness as an indicator of when to change oil is the first such view on this subject that I can remember in many months on this forum. I was not trying to disagree simply to disagree; rather, I was trying to establish or re-establish what the consensus is among the regulars in this forum.
I don't claim enough knowledge on this subject to even case a vote on this issue. I'm simply learning from the other folks here.
Don't recall carbon showing up in the oil analysis?
Jet black, well that would probably bother me. Mine is still amber after 7,500 miles. Makes a huge diff when you look also... Hot oil much clearer then oil sitting overnight.
I'm not disagreeing with those talking about the color change of oil - pro or con. I'm just saying that if I changed my oil when the color turned black in my Cherokees (see post 3479), I would literally be changing it every 1,000 to 1,200 miles. Until I started reading these posts late last year, I didn't even know about oil analysis. Now, the first Cherokee is long gone and the second one has more than 93,000 miles on it. Since I'm still not going to change it any more often than I do (around 3k), I didn't see the point of getting an analysis done. So far, my 02 Explorer doesn't exhibit such behavior, but I still change it's oil between 3 and 4k.
The point of doing the analysis would be to demonstrate that you could actually go 5000, 6000 or even 7000 miles between changes. That could save you big money in the long term if you found that you could do that without hurting the oil or your engine. You would have to do this for each car though.
Are you saying an oil analysis may show that you can go 5K, 6K, or 7K miles between changes on conventional oil, or just full synthetic. I've always gone 10K on full synthetic without a problem, and with some of my vehicles, I probably could've gone longer. But there's no way I would run conventional motor oil longer than 3K. It just doesn't hold up any longer than that.
Jiffy Lube says 3K. Oil companies say 3K. Even though I am a huge syn fan-7.5K is easily possible with conventional oil. Mobil did a test comparingb syn to conventional oil with 7.5K an 15K oil changes. Although the wear was more significant on the conventional oil and one of the cat. converters failed, all cars made it to 200K. They were GM vehicles.
I could see going 15K on full syn, but going that long on dino is nuts! In the real world, no car would last even 100K running dino that long between oil changes. I cringe even thinking about going 7.5K on dino. Then again, I won't use dino in my cars.
A family from USSR. A professional couple, PhD and MS if I remember it right, but they never had a car before immigrating. The first car they bought was very old, and a friend suggested not bothering with maintenance, even oil changes: fresh immigrants have too many thing to learn, in so short time...
About a year later, already with a decent job(s), they bought another car. Something small and cheap, but new. However, they had an impression that cars do not need maintenance. Just did not realise that the suggestions concerning the previous car was for the special surcumstances only.
To make a long story short, the engine run with the factory oil for several years, and died only on 70k+ miles. The couple did not bother with replacing engine, and bought a new car. Bigger, better, and more expensive. Fortunately, could afford.
Small cars with small engines generally are more sensitive to oil quality. So, I firmly believe that many cars would survive to 100k, and even more, with natural oil and 15k miles between changes.
You said "In the real world, no car would last even 100K running dino that long [15k miles] between oil changes."
That's a pretty strong statement. I'm sorry to disagree with you again, as you appear convinced it's because I'm argumentative or don't like you (both not true). But I don't see how anyone could make such a statement and have anything with which to back it up. What makes you so sure?
Would I be willing to test my opinion, that a car would last 100k+ miles with 15k oil change intervals, on a vehicle I owned? No, because I think that is too many miles for oil to last.
I'm thinking there are lots of vehicles on the road whose oil is changed very infrequently.
No, I was not referencing dino or synthetic oils. All I was saying is that the purpose of doing an analysis was to see how long your oil (whatever oil you choose) would last. With some oils in some engines (like maybe Toyota's) the oil may not last 2000 miles before it is worn out. Other oils in other engines may last 15 K and still run great. I think you are making too large of a generalization to say that no car could last more than a 100 K on dino oil changed every 15 K.
yurakm: Please buy a dictionary for goodness sakes and look up the word CIRCUMSTANCES.
Most of you seem to think that cars could last 100K with 15K oil changes, but none of you are willing to do this with your cars. Maybe I should've said that cars could probably last 100K using this change interval, but what shape would they be in? Would you feel comfortable driving this car long distances? I wouldn't.
I don't like dino for several reasons. It just doesn't hold up. There isn't a dino made that I'd run for more than 3K or 4K, and in some small cars, it's not even good for that long. After that, they just turn to crap. They don't resist breaking down in high temps like syn does. They don't flow in the cold like syn does. They don't have the combustion contaminant resistance that syn has. It's more expensive to change dino oil and filter every 3K then it is to change syn oil and filter every 10K. And it's been my experience that engines last longer when full syn is used.
Someone earlier mentioned product specs for Walmart's supertech oil. I received info from PZ/QS about "Walmart Automotive Engine Oil" I asked for syn & blend info, but looks like they sent dino specs. Their page dated was 6/99 & states "SuperTech oils are formulated with high viscosity index, thermally stable base stocks and select additive systems to provide protection for the demands made on modern crankcase lubricants. These oils provide a high level of protection against wear, rust and corrosion, piston scuffing and combustion chamber deposits, high temp oxidation and valve train wear." Anyway it goes on to say the oils are SJ/SH, ILSAC GF-2, energy conserving, and contain shear stable, viscosity index improvers. Respectivly, the 5W30 & 10W30 specs are: VI 155/140; Flash 207/210 (C); Pour -37/-34; Kinetic V 40C/100C 67.0/10.7 - 73.2/11.0. No other info like TBN, Noack, Zinc, etc was provided.
Hopefully someone else will get the synthetic oil data that's also a little more uptodate.
Comments
mdecampsyou will need to wait awhile for the results of the supersyn. Probably 6 months. I will to a 3 rd one for sure on a 2002 Daewoo. That won't be ready until the end of the year.
bigorange30: I hope you are not serious about going 30K on a filter. Filters are so quick, easy and inexpensive. I left the K&N in for 6 months and 6K and that was enough for me.
So, you can go one year on a fitler, after 6 months though my experience is that the drain back valve fails but on a vertical mount who cares.
I stated that the design that Toyota incorporates is excessivily hard on any oil due to the shearing effect by the addition of gears driving the ohc's. This in my book has Never been a design flaw. It has worked prior to 97 with no problems but after the lubrication industry started to incorp the "new" oils out, that's when toyota started to incur more than frequent oil sludge issues. I honestly don't think many were determined to be anything more than ownership's abuse and improper maint until just recently since these numbers had started to increase and internet conectivity giving others the ability to ban together and be heard as one.
with his new 2400 mile oil analysis showing his 30wt oil to be 20wt in that short time supported what I had been saying about tearing most oils up by 4k miles. I have always contributed this problem due the quality of the oil with the design of this engine. This engine has been proven out as an excellent engine but as someone else said, is less forgiving about neglect of maint.
The other point I bring out is sssssoooooo many people pay 20,30 and even up to $40,000 for a vehicle and yet look for the cheapest 9.95 oil change they can get. Man that just really blows my mind on this logic. Kinda like hey doc, I know I need a blood transfusion so you got some cheap stuff?.
I guess there will always be that cheap mentality on oil changes and there will continually be sludge in engines. I just hope that what I have brought to light here was that in my investigations on the toyota v6's, they 1... have an excellent motor. 2... This motor requires a little more attention than most due to its design but has never been an issue of design flaw and that the pcv valve issue they propose was nothing more than a way to inact a little more forgiveness incase of neglect and not a fix for a supposed design flaw...3...Oil quality vs Oil change intervals are a very important factor for proper maint. 4....driving habits are also very critical in selecting drain intervals.
ADC,
I too am interested in your results on the new mobil supersyn but I won't put any weight on the first 2 drains as you'll still have plenty of barrier lube residual from the prior oil and that will be supporting your first 2 oil drains. So by the 3rd oil drain with supersyn, I'd suspect you may see the difference in wear if you do drive like a lot of others and stay up with traffic from light to light If you are like Those that barely ever touch the gas when first taking off, you'll never see much wear due to this not ever breaking the oils hydrodynamic properties.
This is why so many can use one type of oil and so many different analysis will be so different.
Just the same, it should prove out interesting for everyone how it will work out for you.
My personal thoughts on this is that if your wear numbers do not increase by the 3rd oil drain, You are not one that gets on it in traffic much and just take your time accellerating. But if you do stay up with others from light to light, those numbers will increase. Just my opinion and predictions.
Given one is using a good synthetic thats not prone to allow for sludge that would be the only reason why the filter would plug, I don't think that one would generate that much dirt to fill a filter to capacity during everyday driving. I think that the filters limitation is not the synthetic media or construction of filter, yet it's the rubber seal that gives way and looses its holding properties as the rubber seal is constantly exposed to high heat and cold it's grip is sure to loosen additionally depending on the additives used in the oil this may have a bearing on how well that seal will hold up, if one using a synthetic that seal could easily hold up to a year
However if one is using a petrol oil the sealing property may be compromised coupled with high heat and cold to only a 6month limitation.
Anyway I've asked to have the tech sheets for all SuperTech oils dino and syn. sent to me. Will post specs when I get them. Always heard that QS was PAO and Pennzoil wasn't. Don't know if I'll be able to tell that from the spec. sheets or if it really makes any difference.
i think it might have been that i was using ur viewpoint to see something that u were not trying to show.
once more accept my apologies.
Couldn't agree with you more on the over-infatuation (IMO) with sub $1 oil prices. I'm pretty much of a miser. But I'm not penny wise and pound foolish.
Later,
Al
BTW adc100: These oil filters are not cheap. They cost $10-12 each. We're not talking about cheapo Fram filters at $2 each.
http://www.bobistheoilguy.com/
have featured quite a lot of discussion by people much more astute than I am about whether an oil is synthetic unless it's PAO (polyalphaolefin). If you're a Mobil 1 lover you think that this is the definition and that Castrol is the antiChrist for getting their bogus definition of syn. lubricants through the court. Frankly, I've never been convinced that Castrol isn't just as good, even if their oil isn't the real thing.
As far as store brands like SuperTech, their oil filters are first rate, so I have no reason to believe their oils to be bad. Personally I use the $11.99 SuperTech special oil change demanding that the Champion Labs filter be substituted for the Fram. With the exception of never using Fram filters, I have few rules in life.
I was suprised, however, to find that SuperTech oil was a different formulation than Quaker State. I e-mailed the tech because I read in another forum that SuperTech was Pennzoil.
I remember a report several years back that some auto supply sources were relabeling junk (SA non detergent) oil and selling it as name brand stuff in small auto supply stores. At least there's no chance of that happening with Wal-Mart.
http://analystsinc.com/about/locations/analysts_atlanta.htm
bigorange30: You can remove the filter without draining the oil sump as long as the engine isn't running. The oil is pumped from the sump to the filter which is higher than the sump. You will get some oil spillage though, depending on the filter arrangement.
bottgers I still think that 15K is too long to go with a high efficiency filter. I would think there will be a noticable reduction in flow. That could be more critical during very cold weather. There is probably a margin of safety but I would prefer not to test it.
I would also pay the extra to get your TBN included in the analysis.
http://www.blackstone-labs.com/auto.html
The cost is $18.50 w/o the TBN analysis. I don't know yet how much the TBN is extra.
There are a couple of things you can look for that would help you determine how long you can go between oil and filter changes. If you have an oil pressure gage, notice where the gage usually reads, during cold weather and warm, when you first start the car, after it's been running for a while, etc. If you do this right after a fresh oil and filter change, you'll see where the normal indications should be. As you start to get a few thousand miles on the oil and the filter, when the filter starts getting saturated, you'll notice a change in the pressure. Note the mileage, and plan to make your filter changes prior to that mileage from then on.
If you don't have a pressure gage, keep an eye on the color of the oil. Notice how the oil is almost perfectly clear right after an oil change? As you put the miles on that oil, it slowly starts to darken in color. When I change my oil at the 10K mark, whether it's in my Honda or my Intrepid, the oil is a tannish brown color, but you can still see the dipstick through the oil. I never let my oil get any darker than this. If your oil is jet black when you change it, you've gone too long. At that point, the filter is saturated and the only thing it's filtering is rocks. Note the mileage for your next oil and filter change.
These methods aren't scientific, but they've been put to the test, and the results have been favorable.
Later
I don't claim enough knowledge on this subject to even case a vote on this issue. I'm simply learning from the other folks here.
Jet black, well that would probably bother me. Mine is still amber after 7,500 miles. Makes a huge diff when you look also... Hot oil much clearer then oil sitting overnight.
The headline ready Toyota handled "sludge" poorly. After quoting a share of the letter Tom and Ray responded this way.
"Toyota says Sludge happens -- and that it only happens to people who don't change their oil and who do a lot of stop and go driving."
But other independent engineers claim that there is a design problem .... Furthermore it shouldn't happen on low mileage engines."
"But it looks like whatever the cause Toyota handled it poorly by trying to blame it on its customers....."
Toyota should have said "We're sorry you bought a Toyota because you thought it would be worry-free.... We'll fix it. It took Toyota too long."
"These are still excellent cars, in our opinion, and well continue to recommend them."
"We don't expect carmakers to be infallible. We just expect them to own up to their mistakes."
A family from USSR. A professional couple, PhD and MS if I remember it right, but they never had a car before immigrating. The first car they bought was very old, and a friend suggested not bothering with maintenance, even oil changes: fresh immigrants have too many thing to learn, in so short time...
About a year later, already with a decent job(s), they bought another car. Something small and cheap, but new. However, they had an impression that cars do not need maintenance. Just did not realise that the suggestions concerning the previous car was for the special surcumstances only.
To make a long story short, the engine run with the factory oil for several years, and died only on 70k+ miles. The couple did not bother with replacing engine, and bought a new car. Bigger, better, and more expensive. Fortunately, could afford.
Small cars with small engines generally are more sensitive to oil quality. So, I firmly believe that many cars would survive to 100k, and even more, with natural oil and 15k miles between changes.
However, I would not experiment with my car.
That's a pretty strong statement. I'm sorry to disagree with you again, as you appear convinced it's because I'm argumentative or don't like you (both not true). But I don't see how anyone could make such a statement and have anything with which to back it up. What makes you so sure?
Would I be willing to test my opinion, that a car would last 100k+ miles with 15k oil change intervals, on a vehicle I owned? No, because I think that is too many miles for oil to last.
I'm thinking there are lots of vehicles on the road whose oil is changed very infrequently.
Why are you so down on conventional oil?
yurakm: Please buy a dictionary for goodness sakes and look up the word CIRCUMSTANCES.
And my spoken English is even worse, I would say much worse :-(
I don't like dino for several reasons. It just doesn't hold up. There isn't a dino made that I'd run for more than 3K or 4K, and in some small cars, it's not even good for that long. After that, they just turn to crap. They don't resist breaking down in high temps like syn does. They don't flow in the cold like syn does. They don't have the combustion contaminant resistance that syn has. It's more expensive to change dino oil and filter every 3K then it is to change syn oil and filter every 10K. And it's been my experience that engines last longer when full syn is used.
Hopefully someone else will get the synthetic oil data that's also a little more uptodate.